<template>
  <div class="type-nav">
    <div class="container">
      <h2 class="all" @mouseenter="isShow=true" @mouseleave="changeIsShow1">全部商品分类</h2>
      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
      <!-- Vue 在插入、更新或者移除 DOM 时，提供多种不同方式的应用过渡效果 -->
      <transition name="sort">
        <div class="sort" v-show="isShow" @mouseenter="changeIsShow2" @mouseleave="changeIsShow3">
        <div class="all-sort-list2" @click="goSearch">
          <div class="item" v-for="c1 in categoryList" :key="c1.categoryId" :class="{isTouch:touchIndex===c1.categoryId}">
            <h3 @mouseenter="changeTouchIndex(c1.categoryId)" @mouseleave="touchIndex=-1">
              <a :data-categoryName='c1.categoryName' :data-category1Id='c1.categoryId'>{{c1.categoryName}}</a>
            </h3>
            <div class="item-list clearfix" @mouseenter="changeTouchIndex(c1.categoryId)" @mouseleave="touchIndex=-1">
              <div class="subitem" v-for="c2 in c1.categoryChild" :key="c2.categoryId">
                <dl class="fore">
                  <dt>
                    <a :data-categoryName='c2.categoryName' :data-category2Id='c2.categoryId'>{{c2.categoryName}}</a>
                  </dt>
                  <dd>
                    <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                      <a :data-categoryName='c3.categoryName' :data-category3Id='c3.categoryId'>{{c3.categoryName}}</a>
                    </em>
                  </dd>
                </dl>
              </div>
            </div>
          </div>
        </div>
        </div>
      </transition>
    </div>
  </div>
</template>

<script>
import {mapState} from 'vuex'
// import _ from 'lodash' 这是全部引入
import throttle from 'lodash/throttle' //按需引入

export default {
  name: "TypeNav",
  mounted() {
    // 调接口拿数据
    this.$store.dispatch('getCategoryList')
    if(this.$route.path!=='/home'){
      this.isShow=false
    }
  },
  computed:{
    ...mapState({
      categoryList:state=>state.home.categoryList
    })
  },
  data() {
    return {
      touchIndex:-1,
      isShow:true
    }
  },
  methods: {
    // 引入节流操作
    changeTouchIndex:throttle(
      function(id){
        this.touchIndex=id
      },50
    ),
    goSearch(event){
      // 用自定义属性解决事件委派产生的问题
      let element=event.target
      let {categoryname,category1id,category2id,category3id}=element.dataset
      // 如果有categoryname这个自定义属性，那么他是a标签
      if(categoryname){
        let location={name:'search'} //整理路由参数
        let query={categoryName:categoryname}
        // 如果有category1id这个自定义属性，那么他是一级分类，同理可得
        if(category1id){
          query.category1Id=category1id
        }else if(category2id){
          query.category2Id=category2id
        }else{
          query.category3Id=category3id
        }
        location.query=query
        // // 路由跳转
        if(this.$route.params){
          location.params=this.$route.params
          this.$router.push(location)
        }else{
          this.$router.push(location)
        }
      }
    },
    changeIsShow1(){
      if(this.$route.path!=='/home'){
        this.isShow=false
      }
    },
    changeIsShow2(){
      if(this.$route.path!=='/home'){
        this.isShow=true
      }
    },
    changeIsShow3(){
      if(this.$route.path!=='/home'){
        this.isShow=false
      }
    }
  },
};
</script>

<style scoped lang='less'>
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .isTouch{
          background-color: skyblue;
        }
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          &:hover {
            .item-list {
              display: block;
            }
          }
        }
      }
    }
    // 过渡动画
    // 进入开始
    .sort-enter{
      height: 0;
    }
    // 进入结束，v-enter的样式被移除
    .sort-enter-to{
      height: 461px;
    }
    // 定义动画效果
    .sort-enter-active{
      transition: all 0.3s linear;
    }
  }
}
</style>